Method of forming and trimming die castings



Jan. 16, 1945. 1.. H. MORIN 2,367,235

METHOD OF FORMING AND TRIMMING DIE CASTINGS Filed Aug. 15, 1942 INVENTOR lows H. Mom/v BY 5i ATTORNES Patented Jan. 16, 1945 I METHOD OF FORMING AND TRIMMING DIE CASTINGS Louis H. Morin, Bronx, N. Y., assignor of onehalf to Davis Marinsky, Bronx, N Y.

Application August 15, 1942, Serial No. 454,922

7 Claims.

This invention relates to the formation of die castings. More particularly, the invention relates to a method of forming castings comprisinga product part and a gate part, each part being formed on an independent core and in utilizing the movement of these cores to strip said parts and trim the gate part from the product part during the stripping operation. The novel features of the invention will 'be best understood from the 'following description when taken together with the accompanying drawing, in which of casting having a core portion can be produced. The dies also have recesses I2, which pass centrally through cavity II, and are adapted to certain embodiments of the invention are dis- 7 closed, and in which the separate parts are designated by suitable reference characters in each of the views; and in which:

Fig. l is a diagrammatic view showing the formation of the complete casting.

Fig. 2 is a view similar to Fig. 1 showing the casting moved out of alinement with the dies preparatory to the stripping operation.

Fig. 3 is a view similar to Figs. 1 and 2, showing the stripping and trimming operation; and,

Fig. 4' is a view similar to Figs. 1 to 3, illustrating the completion of the stripping operation with the dies and cores in position preparatory for the next casting operation.

In the art of forming die castings, it has been common practice to first form a casting and'then, after removing the casting from the machine, to trim the casting to remove the gate and other portions therefrom. In certain types of machines trimming tools have been employed as part of the casting machine to trim the casting prior to the delivery of the finished product from the machine.

It is the purpose of my .present method tomatenially simplify the production of the finished cast products by providing a simple method of performing the trimming operation, or in other words, of removing the gate part from the product part of the casting. This simple and economical method of procedure is set forth in the following description.

For the purpose of illustrating one adaptation of my invention I have diagrammatically illustrated in the several figures, one member III of a die, viewing this die on the parting line of the two dies which are moved toward and from each other in the usual manner.

Also to lllustrateone adaptation of the invention, the die or dies have impressions or cavities 'l I, to form a resulting casting product in the form of a sleeve. This product is made of simple structure, merely to simplify the illustration,

but it will be apparent that any type and kind receive a core pin I 3 which extends longitudinally of the cavity l I, and on which the resulting casting product part M is formed. Also opening into the cavity II are gate passages I5, with the admission end IB'of which is adapted to register a nozzle l1, through which casting material is adapted to be pressure injected into the cavity II as will be apparent. another vertical passage I8 parallel to the passage |2, for receiving a core l9 and the gate passage |5 encircles the core IS in a ring-like angular passage 20, which is arranged angularly on thecore l9 in the manner clearly seen in the several figures. This angularity of the gate passage offsets the admission end l6 thereof from the end of the passage where it enters thecavity Further, the angular arrangement of the ring portion 20 on the core pin I9 retains the gate against shifting on the pin in the initial stripping operation for purposes later described.

The surface 2| of the dies immediately below the cavity II is of greater depth than the surface 22 whichis in alinement with the gate end portion 23.

In the operation of forming and trimming the casting, the dies are first closed around the core pins l3 and I9, and casting material is pressure injected into the cavity through the gate and this forms upon both of the core pins the cylindrical product part I4 including the integral gate part 24. The dies are now separated and both of the core pins are moved downwardly to bring the casting below the surfaces 2|, 22 as seen in Fig. 2. The dies are now partially closed and the core pins are moved upwardly in the stripping operation. In the beginning of this operation, the surface 2| first strikes the product part M and strips or severs this part from the gate part 24 while leaving ,the gate part still firmly supported on the core pin l9. By reference to Fig. 3, it will-appear that the gate part 24 has not yet engaged the surface 22; however, as the core pins continue to move upwardly the product part It. and the gate-part 24 will be completely stripped from the core pins and delivered to separate compartments, which are subdivided by a partitioning member 25, note Fig. 4. At the completion of the upward movement of the core pins the same are returned to their normal casting position, the diesare then again completely closed and the above cycle of operation repeated.

While the gate part 24 is firmly supported on The die or dies also have the core pin l9 during the trimming or severing operation, it will be apparent that the minute the end portion 23 engages the surfaces 22, the gate part will be freely stripped from the pin IS.

The casting product part l4 may be said to comprise the primary product part and in some instances, the gate part as at 24 may actually be fashioned to form a useable product, for example, the ring-like body 20 may be used as a washer, however, the dies may be constructed to shape or characterize the gate portion to produce, within the limits of the particular machine, supplemental product parts which may be trimmed or processed in old and conventional manners.

It will also be understood that regardless of the shape or contour of the gate part, or what might be termed the supplemental product part, there will always be established between it and primary product part a weakened .point of contact which will facilitate the trimming or severing operation in accordance with the method herein defined, namely, relative movement between the two parts in a strip operation and while both parts are still in engagement with their respective core pins.

In the present construction the end 26 of the product part l4, note Fig. 2, is above the end 23 of the gate .part 24 and this, in combination with the different heights of the surfaces 2| and 22, facilitates the trimming or severing operation. In some instances, the corresponding surfaces of the product parts may be suiiiciently spaced to provide the desired trimming or severing operation without altering or recessing the lower surfaces of the dies.

Having fully described my invention what I claim as new and desire to secure by Letters Patent is:

1. The method of producing die castings, comprising the steps of first forming, between relatively movable dies and on a pair of core pins supported on the parting line of the dies, a casting comprising a product part and an integral gate part, forming the casting by pressure injection of material into the dies with the product part engaged by one core pin and the gate part engaged by the other core pin, then opening the dies and simultaneously feeding both core pins to move the casting out of alinement with the dies, then partially closing the dies and'moving the core pins in they opposite direction to strip the casting therefrom, moving one of said parts on its core pin while holding the other part against movement-on its core pin in said stripping operation to provide relative movement between said parts to sever or trim the gate part from the product part, and delivering the separate parts from'the pins on the completion of the stripping operation.

2. The method of forming and trimming castings to deliver independent product and gate parts from said castings, which comprises forming a die casting on two parallel core members arranged on the parting line of relatively movable dies, by pressure injection of casting material into the dies the casting comprising a product part on one core member and a gate part on the other core member, separating the dies and moving both core members to bring the casting beyond one surface of the dies, then par-.

- tially closing the dies and moving the core members in the opposite direction to strip the cast ing from the core members by engagement with said parts of the casting resulting in the severance of the gate part from the product part, and then continuing said last named movement of the core members to completely strip the severed product and gate parts for delivery into receiving receptacles.

3. The method of producing and trimming castings, comprising first forming a unitary cast body on spaced parallel core members arranged on the parting line of relatively movable dies, then opening the dies and moving the core members relatively to the dies in one direction, then .partially closing the dies, then moving the core members in the opposite direction establishing differential movement between that part of the casting on one core member with the part of the casting on the other core member, to sever said parts leaving each suspended on each core memher, and then, on completing the last named movement of the core members, stripping both of said parts and delivering the same into independent receptacles.

4. In the formation of die casting comprising product and gate parts, the method of first forming the casting on spaced parallel core pins arranged between impression surfaces of relatively movable dies, separating the dies and moving the castings by said core pins out of alinementwith said impression surfaces, then severing the product part'from the gate part by sliding one of said parts longitudinally of its core pin while retaining the other part against movement on its core pin, and then finally stripping the severed parts from both core pins.

5. In the formation of die castings comprising two integrally formed parts, the method of first forming a casting with each part on an independent core pin arranged between impression surfaces of relatively movable dies, separating the dies and moving the casting by said core pins out of alinement with said impression surfaces, then severing said'parts one from the other by sliding one of said parts longitudinally of its core pin while retaining the other part against movement on its core pin and then stripping the severed parts from the core pins and delivering the same from the casting machine.

6. The method of trimming die casting comprising two parts cast united in a single casting, which comprises first forming a casting with each part thereof disposed on an independent member, removing the casting from the die in which it is formed, then trimming the one part from the other by moving the said independent casting comprising two parts joined by an inter- Y mediate weakened portion, forming eacli part on an independent supporting member, removing the casting from the die in whichit is formed then moving said supporting members 'while bers.

keeping onepart immovable to sever said parts at said weakened portion, and then removing both of said parts from their supporting meme Loms H. MORIN. 

